This invention is in the field of wire splicing. Further the invention provides means to protect the splice environmentally.
Wire splicing devices range from twisting the ends of two wires together to a more recent innovation utilizing wire-receiving slots wherein the edges of the slots cut through the insulation and make electrical contact with the underlying conductor. As the present invention uses wire-receiving slots only the prior art disclosing such splicing means will be discussed.
The earliest patent known to Applicant disclosing wire-receiving slots is U.S. Pat. No. 2,501,187 issued to Jan Oortgijsen. Subsequent patents include U.S. Pat. No. 3,012,219 and more recently U.S. Pat. No. 3,860,318, the latter advancing the art considerably by the successful termination of two wires in a single slot.
The slot designs have remained relatively unchanged so far as single wire termination is concerned. The blades; i.e., the slot-carrier, have changed in shape, positioning and in number. For example, compare the blade in the aforementioned U.S. Pat. No. 3,012,219 with the dual-in-line cantilever blades in U.S. Pat. No. 3,864,011.
The method of terminating a wire has generally remained the same; i.e., the edges of the slot cut through the insulation and make electrical contact with the underlying conductor. In some devices the wire is moved; in other the blades are moved; an example of the latter is disclosed in U.S. Pat. No. 3,920,305.
The method of supporting the blades has varied. For example, the blade disclosed in U.S. Pat. No. 3,012,219 is positioned in a deep groove cutting across the wire support surface. The blade disclosed in U.S. Pat. No. 3,836,944 is supported on its ends by vertical grooves in the insulating housing.
In addition to the patents noted above, other wire-in-slot patents include, but are not limited to, U.S. Pat. Nos. 3,388,370; 3,444,506; 3,874,764 and 3,912,356. In each of the noted patents and in other known but not listed patents which splice two or more wires together, one characteristic stands out. The wire-in-slot splice devices consist of one or more blades each having two slots and some means for retaining the wires in the slots. Generally the means is a cover or lid which closes down onto the blade-containing base to provide both an insulation and a wire-retaining means. In other words, all the known devices must include two elements; the blade and the wire-retaining means.
As is well known, bare electrical conductors connected to a terminal of some type or spliced together offer a point of least resistance to attack by corrosive agents in the environment. And, as is also well known, corrosion increases the resistance and ultimately destroys the connection or splice.
Solutions to preventing corrosive attack include plastic waterproof tape, unctuous grease, heat shrinkable sleeves and tapes and housing surrounding the connection or splice which can be sealed. Obviously, the variety of solutions touched upon above represent solutions to particular problems. For example, the method of providing protection for a splice on the telephone cables underyling the streets of New York City require enclosing the splice area with a bulky resin-filled sleeve such as disclosed in U.S. Pat. No. 2,957,038. A method for protecting spliced electrical mining cable using a resilient sleeve is disclosed in U.S. Pat. No. 3,824,331.
With particular reference to wire splicing devices, one prior art device known to Applicant is a connector made and sold under the trademark SCOTCHLOK by the Minnesota Mining and Manufacturing Company. This connector consists of a housing having a movable cap and two or more wire-in-slot contact blades in a cavity which is filled with a waterproof grease. After the wires are inserted into the cavity and on top of the contact blades, the cap is pushed down into the cavity to drive the wires into the slots to establish a common to provide both an insulation and a wire-retaining means. In other words, all the known devices must include two elements; the blade and the wire-retaining means.
As is well known, bare electrical conductors connected to a terminal of some type or spliced together offer a point of least resistance to attack by corrosive agents in the environment. And, as is also well known, corrosion increases the resistance and ultimately destroys the connection or splice.
Solutions to preventing corrosive attack include plastic waterproof tape, unctuous grease, heat shrinkable sleeves and tapes and housing surrounding the connection or splice which can be sealed. Obviously, the variety of solutions touched upon above represent solutions to particular problems. For example, the method of providing protection for a splice on the telephone cables underlying the streets of New York City require enclosing the splice area with a bulky resin-filled sleeve such as disclosed in U.S. Pat. No. 2,957,038. A method for protecting spliced electrical mining cable using a resilient sleeve is disclosed in U.S. Pat. No. 3,824,331.
With particular reference to the present invention, the single prior art device known to Applicant is a connector made and sold under the trademark SCOTCHLOK by the Minnesota Mining and Manufacturing Company. This connector consists of a housing having a movable cap and two or more wire-in-slot contact blades in a cavity which is filled with a waterproof grease. After the wires are inserted into the cavity and on top of the contact blades, the cap is pushed down into the cavity to drive the wires into the slots to establish a common electrical bond therebetween. The combined specifically designed housing and grease provides an environmentally protected splice.